"Bieber performed 'Somebody to Love' on multiple occasions, including as a part of his set list on the My World Tour." → remove "as a part of his set list on". Also, shouldn't it be Bieber "has" performed?
"part of his set list" is relevant because otherwise it may be thought that he performed it on the tour on one or however number of occasions, but this denotes that it was a set part of the tour on each date.
alongside "Baby" and other of his previous songs. → Hmmm... maybe rewording?
"Bieber performed 'Somebody to Love' on multiple occasions, including as a part of his set list on the My World Tour." → remove "as a part of his set list on". Also, shouldn't it be Bieber "has" performed?
"part of his set list" is relevant because otherwise it may be thought that he performed it on the tour on one or however number of occasions, but this denotes that it was a set part of the tour on each date.
alongside "Baby" and other of his previous songs. → Hmmm... maybe rewording?